Popping beans, or Ă±uĂ±as as they are called in Peru, belong to an indeterminately growing varietal group of common beans, whose seeds expand upon toasting. They are a popular snack in parts of Peru and Ecuador, but little known outside their very limited â€śinsularâ€ť distribution. While the plant is virtually indistinguishable from regular beans, the seeds of Ă±uĂ±as tend to be round and opaque. Traditionally, Ă±uĂ±as have been grown in association with maize, but high-yielding maize is susceptible to logging under the weight of the bean vines. A breeding programme at INIA, Peru, is selecting superior material from farmer selections showing early maturity and determinate growth, in the hope that such selections would succeed in market-oriented cropping systems.